Water has an equilibrium vapor pressure of 23.8 mm Hg at 25 C. If 1.00 g H2O is sealed in a 20 L flask, what mass will remain in the liquid phase when equilibrium is established? ( 760 mmHg = 1 atm, R =0.0821 L.atm/mol.K)

Answer 1

I would solve PV = nRT for n to determine moles of gas that can be accommodated in the 20L flask. Then compare that with the number of moles H2O available.